TsAGI (ЦАГИ) - the 'Central Aerohydrodynamic Institute' in Russia (Центра́льный аэрогидродинами́ческий институ́т) has begun serious and complex design work for a quiet supersonic business jet that could fly over populated areas!

 

Here's an official early concept image:

 

The institute will develop the preliminary design in partnership with several Russian companies, including 'Sukhoi' and 'NPO Saturn'.

 

One of the primary issues with Supersonic Transport Planes 'SSTs' (apart from cost) has been their sonic boom (or more specifically the sonic booms they generate while in supersonic flight):

 

 

which has resulted in SSTs being prohibited on going supersonic over populated areas. Additionally there is also the higher engine noise levels on SSTs and the significantly higher thrust they need compared to other aircraft. SSTs generally provide poor performance in slow flight - they have poor lift/drag ratios at subsonic speeds (unless swing wing technology is employed) and burn more fuel in these circumstances. Supersonic aircraft are designed to go fast, if they are not going supersonic then they are pretty far from being cost effective.

The solution Concorde applied to these problems was to wait until the aircraft is at high altitude and over water before reaching supersonic speeds. However in the end this is just a technique to go around the problem and doesn't address it - supersonic flight over populated areas was still not possible, thus limiting the use of the Concorde and meaning the aircraft can only be used cost effectively for routes over oceans.

 

If TsAGI can develop a quiet supersonic business jet it would be a great achievement, which would in turn encourage more work on developing effective SST airliners.

In Russia, since the 90s, both Tupolev and Sukhoi have been involved in creating designs for supersonic business jets.

 

Research so far has indicated that it is certainly possible to design a quiet supersonic jet - there are even theoretical designs that do not appear to create sonic booms at all! Careful shaping of the fuselage of the aircraft can reduce the intensity of the sonic boom's shock waves that reach the ground. During 2003, a Shaped Sonic Boom Demonstration aircraft was flown by NASA, which demonstrated the capability to reduce the sonic boom by about half. There has also been 'Quiet Spike' and even designs involving causing the shock waves to interfere with each other. Just lengthening the aircraft (without significantly increasing its weight) seems to reduce the boom intensity. With the increasing power of computer-aided design it has become possible and much easier to develop and test such designs.

 

The only SSTs to see regular service to date have been Concorde and the Tupolev Tu-144. It would be great to finally start seeing new successful types being developed and created.

Interesting. Would like to hear a sonic boom someday. Have no clue what its like.

When I was a child, I was on holiday very near the Soviet AFB on the Baltic Sea coast. Damn it was noisy... Mach1 was reached on very low levels, above the sea (so no trees, buildings etc to dissipate the SB).I'd like to hear and see it again.

Interesting. Would like to hear a sonic boom someday. Have no clue what its like.

Can get some idea from here:

http://soundbible.co...Sonic-Boom.html

 

and here:

 

 

I've only heard the real thing once, best way I can describe it is that it was a loud 'Boom' sound.

 

I always found it interesting that if you happen to be on the aircraft creating the sonic boom you wouldn't be able to hear it, as its now travelling faster than the speed of sound and the sound wave cannot catch up with the aircraft.

 

Here's what the sound waves look like as the Supersonic aircraft is breaking the sound barrier and moving at Mach 1. It has just started to move slightly ahead of the sound waves its creating:

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When the aircraft is going supersonic at over Mach 1.4 - The sound source (the aircraft) has now broken through the sound speed barrier and is moving considerably faster than the sound waves it creates.

 

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and here, just to compare, are the sound waves from a normal airliner going at about Mach 0.7: